scholarly journals Anatomopathological pneumonic aspects associated with highly pathogenic Pasteurella multocida in finishing pigs

2017 ◽  
Vol 37 (10) ◽  
pp. 1091-1100 ◽  
Author(s):  
Eliana S. Paladino ◽  
Michelle de P. Gabardo ◽  
Priscilla N. Lunardi ◽  
Nelson Morés ◽  
Roberto M.C. Guedes
Keyword(s):  
Respiratory Disease ◽  
Influenza A ◽  
Pasteurella Multocida ◽  
Systemic Infection ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus ◽  
Clinical Samples ◽  
Finishing Pigs ◽  
Virulence Markers ◽  
Gross Lesions

ABSTRACT: The bacterium Pasteurella multocida is a frequent cause of porcine respiratory disease complex in finishing pigs. Historically, the bacterium is recognized as an opportunistic agent, causing secondary bacterial pneumonia in pigs. Several Brazilian reports have suggested the ability of P. multocida to cause primary pulmonary infection that leads to the death of finishing pigs prior to slaughter. The aim of this study was to evaluate anatomopathological pulmonary findings associated with P. multocida infection that were obtained from animals with clinical respiratory disease and from animals at slaughter. Twenty-five lung samples from 14 herds of finishing pigs with acute clinical respiratory disease and 19 lungs collected at slaughter from a different set of 14 herds were studied. In all lung samples, bacterial isolation was performed, and only samples with pure P. multocida growth were included in the study. Gross and histopathological lesions were evaluated, as well as Influenza A, porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae co-infections. Pleuritis and pericarditis were more often observed in clinical samples (P<0.05). Moreover, there was a numerical trend indicating that pericarditis, lymphadenomegaly and cavity exudates were more often present in clinical samples. Thirteen lung samples were negative to M. hyopneumoniae, Influenza A and PCV2 by immunohistochemistry (IHC), with only P. multocida identified. In these cases, gross lesions such as pleuritis, pericarditis and lymphadenomegaly were always present, and no histologic lesions indicative of other agents such as Actinobacillus pleuropneumoniae, Actinobacillus suis or Haemophilus parasuis were observed. These findings suggest the ability of some P. multocida isolates to cause primary respiratory and systemic infection. However, in this study, it was not possible to determine specific virulence markers to explain these findings.

scholarly journals Assessment of Lung Disease in Finishing Pigs at Slaughter: Pulmonary Lesions and Implications on Productivity Parameters

Animals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3604
Author(s):  
Yania Paz-Sánchez ◽  
Pedro Herráez ◽  
Óscar Quesada-Canales ◽  
Carlos G. Poveda ◽  
Josué Díaz-Delgado ◽  
...  
Keyword(s):  
Respiratory Disease ◽  
Lung Parenchyma ◽  
Porcine Circovirus Type ◽  
Daily Weight Gain ◽  
Porcine Circovirus ◽  
Respiratory Syndrome Virus ◽  
Finishing Pigs ◽  
Negative Impacts ◽  
The Impact

Swine respiratory disease is associated with productive losses. We evaluated the prevalence of lung lesions with an emphasis on Mycoplasma hyopneumoniae (Mh), porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV), as well as the impact on productive parameters in 108 finishing pigs at slaughter. Pathologic, immunohistochemical (IHC) and serologic analyses were performed. Pneumonic processes were observed in 73.1% of the animals. They mainly consisted of cranioventral bronchopneumonia (CBP) (46.3%) and pleuritis (17.6%). Microscopically, bronchointerstitial pneumonia (67.4%) was common and was occasionally combined (27.9%) with interstitial pneumonia (IP). Mh and PCV2-antigens were detected in bronchointerstitial pneumonia (70.7%) and IP cases (33.3%). There were low titers against Mh (18%) and high titers against PRRSV (100%) and PCV2 (65%). Animals with CBP remained at the farm longer; those with >10% of lung parenchyma involvement were sent later (208.8 days old) and had a lower average carcass weight (74.1 kg) and a lower daily weight gain (500.8 gr/day) compared with animals without lesions (567.2 gr/day, 77.7 kg, 200.8 days old). We suggest that animals that do not reach the weight at slaughter should be sent to slaughter regardless to avoid further negative impacts of respiratory disease in productive parameters.

scholarly journals Agents of pneumonia in slaughtered pigs in southern Brazil

2021 ◽  
Vol 41 ◽  
Author(s):  
Elisa R. De Conti ◽  
Karine L. Takeuti ◽  
Claiton I. Schwertz ◽  
Ronaldo M. Bianchi ◽  
David Driemeier ◽  
...  
Keyword(s):  
Real Time ◽  
Influenza A ◽  
Pasteurella Multocida ◽  
Histopathological Examination ◽  
Infectious Agent ◽  
Finishing Pigs ◽  
Southern Brazil ◽  
Rt Pcr ◽  
Gross Lesions ◽  
Slaughtered Pigs

ABSTRACT: A high prevalence of pneumonic lesions has been reported to affect slaughtered pigs in southern Brazil. In order to identify which microorganisms have been causing those lesions, 30 pig lungs presenting pneumonic gross lesions were collected from five different slaughterhouses, totaling 150 lungs. Samples for bacterial isolation, molecular, histopathologic and immunohistochemistry (IHC) evaluation were taken from each lung. The pneumonic lesion scoring ranged from 1.53 to 2.83. The most frequent histopathological lesions found was the concomitant Influenza A virus (IAV) and Mycoplasma hyopneumoniae infection, corresponding to 55.3% (83/150), and Pasteurella multocida type A was isolated in 54.2% (45/83) of these cases. In 102 samples (68%), there was histopathologic suggestion of involvement of more than one infectious agent. M. hyopneumoniae was the most frequent agent associated with pneumonic lesions, being present in 92.1% (94/102) of the lungs with coinfections, followed by IAV in 89.2% (91/102). Besides the coinfections, IAV lesions were observed also in six samples without another pathogenic microorganism detected. A total of 46 samples with acute and subacute IAV suspected lesions in histopathological examination were assessed for IHC and real time RT-PCR for IAV. A total of 35% (16/46) of them were positive by IHC and 13% (6/46) by real time RT-PCR. Regarding M. hyopneumoniae, 79.3% (119/150) of samples were positive by qPCR and 84.9% (101/119) of them also presented M. hyopneumoniae suspected lesions in the histopathological examination. The results of this study suggest the importance of IAV in respiratory diseases in finishing pigs, even though this virus is more frequently reported in the nursery phase. In addition, our results emphasize the importance of lung coinfections in finishing pigs.

scholarly journals Causes of death in growing-finishing pigs in two technified farms in southern Brazil

2020 ◽  
Vol 40 (10) ◽  
pp. 758-775
Author(s):  
Manoela M. Piva ◽  
Claiton I. Schwertz ◽  
Ronaldo M. Bianchi ◽  
Regina T. Kemper ◽  
Luan Cleber Henker ◽  
...  
Keyword(s):  
Infectious Diseases ◽  
Influenza A ◽  
Pasteurella Multocida ◽  
Causes Of Death ◽  
Histopathological Examination ◽  
Gastric Ulcers ◽  
Finishing Pigs ◽  
Southern Brazil ◽  
Bacterial Pericarditis ◽  
Conclusive Diagnosis

ABSTRACT: The aim of this study was to investigate the main causes of death in growing-finishing pigs in southern Brazil. During a one-year period (from 2018 to 2019), two industrial pig herds (18 and 20 thousand pigs each farm) in southern Brazil were monitored along the four seasons of the year (12 days per season on each farm), in order to perform necropsies of all pigs that died in that period. The two farms had an average monthly mortality rate ranging from 0.94 to 3.93% in the evaluated months. At necropsy, tissues were collected, fixed in 10% formalin solution and processed routinely for histopathological examination. When necessary, samples were sent for bacterial culture and PCR to identify etiologic agents. A total of 601 necropsies were performed, with 94.9% of conclusive diagnoses. Infectious diseases corresponded to 64.4% of conclusive diagnosis and non-infectious diseases to 35.6%. The most prevalent causes of death were: pneumonia (33%), gastric ulcers (15.4%), circovirosis (9.9%), systemic bacterial embolism (5.4%), polyserositis (4.4%), dilated cardiomyopathy and torsion of abdominal organs (4.3% each), and bacterial pericarditis (3.4%). Regarding pneumonias (199/601), the main agents identified in these cases were Pasteurella multocida, Influenza A virus and Mycoplasma hyopneumoniae, mainly in associations.

scholarly journals Survey Of Infectious Agents Associated With Porcine Respiratory Disease Complex (PRDC) In Serbian Swine Herds Using Polymerase Chain Reaction (PCR) Detection

2015 ◽  
Vol 65 (1) ◽  
pp. 79-88 ◽  
Author(s):  
SAVIĆ Božidar ◽  
RADANOVIĆ Oliver ◽  
JOVIČIĆ Dubravka ◽  
NEŠIĆ Ksenija ◽  
IVANOVIĆ Snežana ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Respiratory Disease ◽  
Respiratory Virus ◽  
Mycoplasma Hyopneumoniae ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Porcine Respiratory

Abstract A retrospective study on 235 natural cases of Porcine Respiratory Disease Complex in order to determine the etiological agents, their prevalence and interrelationships was performed in Serbia. Lung tissue samples were analyzed by Polymerase Chain Reaction for the presence of Porcine circovirus type 2, Porcine reproductive and respiratory virus, Swine influenza virus, Mycoplasma hyopneumoniae, Pasteurella multocida, Actinobacillus pleuropneumoniae, Haemophilus parasuis, Streptococcus suis and Arcanobacterium pyogenes. A total of 49 different combinations of viral and bacterial pathogens were found. Five different viral and viral/Mhp co-infections were detected. Monobacterial infections were found in 150 cases and polybacterial infection was detected in 85 samples. PCV2 was the main virus detected, and Pm was the most aggressive secondary pathogen detected in PRDC. The reason for PRDC being so prevalent among Serbian pigs is most likely due to the large number of risk factors in the conventional farrow-to-finish system, compared to multi-site production systems. Therefore, measures aimed at a better control of respiratory viruses, particularly Porcine circovirus type 2 and Porcine reproductive and respiratory virus, as well as Mycoplasma hyopneumoniae infections, and adoption of rational decisions on respiratory bacterial pathogens specific therapeutic and preventive strategies at herd level, simultaneously with significant improvements on farm management should reduce the occurrence of PRDC.

scholarly journals Causes of swine polyserositis in a high-density breeding area in Italy

2020 ◽  
Vol 32 (4) ◽  
pp. 594-597
Author(s):  
Cristian Salogni ◽  
Massimiliano Lazzaro ◽  
Stefano Giovannini ◽  
Nicoletta Vitale ◽  
Maria Beatrice Boniotti ◽  
...  
Keyword(s):  
Influenza A ◽  
Pasteurella Multocida ◽  
Swine Influenza ◽  
High Density ◽  
Porcine Circovirus ◽  
Respiratory Syndrome Virus ◽  
Strong Positive Correlation ◽  
Breeding Area ◽  
Causative Agents ◽  
Bacterial Coinfection

We assessed the causes of polyserositis in pigs, categorized by causative agents and ages of animals affected. In a 3-y study, 246 pigs from 80 different farms with recurrent problems of polyserositis, in a high-density breeding area, were submitted for autopsy; 154 pigs with typical fibrinous serosal lesions were sampled for further bacterial and viral investigation. The most common gross lesions were pleuritis and pericarditis (141 of 154; 92%). The animals most affected were weaned pigs (139 of 154; 90%). Haemophilus parasuis and Mycoplasma hyorhinis were the most common bacteria detected and were present at the same rate (85 of 154; 55%). Other bacteria isolated were Streptococcus sp. (44 of 154; 29%), Pasteurella multocida (21 of 154; 14%), Escherichia coli (19 of 154; 12%), Actinobacillus pleuropneumoniae (7 of 154; 5%), and Trueperella pyogenes (4 of 154; 3%). Porcine reproductive and respiratory syndrome virus (PRRSV; 119 of 154; 77%) predominated among the viruses detected, followed, with lesser prevalence, by porcine circovirus 2 (40 of 154; 26%) and swine influenza A virus (19 of 154; 12%). Bacterial coinfection and coinfection of bacteria and viruses were common (128 of 154; 83%). A strong positive correlation was found between coinfection by H. parasuis and M. hyorhinis and also by H. parasuis with PRRSV.

Polymicrobial respiratory disease in pigs

2011 ◽  
Vol 12 (2) ◽  
pp. 133-148 ◽  
Author(s):  
T. Opriessnig ◽  
L. G. Giménez-Lirola ◽  
P. G. Halbur
Keyword(s):  
Respiratory Disease ◽  
Pasteurella Multocida ◽  
Bacterial Pathogens ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
The Body ◽  
Detection Methods ◽  
Porcine Circovirus ◽  
Respiratory Syndrome Virus ◽  
Respiratory Pathogens

AbstractRespiratory disease in pigs is common in modern pork production worldwide and is often referred to as porcine respiratory disease complex (PRDC). PRDC is polymicrobial in nature, and results from infection with various combinations of primary and secondary respiratory pathogens. As a true multifactorial disease, environmental conditions, population size, management strategies and pig-specific factors such as age and genetics also play critical roles in the outcome of PRDC. While non-infectious factors are important in the initiation and outcome of cases of PRDC, the focus of this review is on infectious factors only. There are a variety of viral and bacterial pathogens commonly associated with PRDC including porcine reproductive and respiratory syndrome virus (PRRSV), swine influenza virus (SIV), porcine circovirus type 2 (PCV2),Mycoplasma hyopneumoniae(MHYO) andPasteurella multocida(PMULT). The pathogenesis of viral respiratory disease is typically associated with destruction of the mucocilliary apparatus and with interference and decrease of the function of pulmonary alveolar and intravascular macrophages. Bacterial pathogens often contribute to PRDC by activation of inflammation via enhanced cytokine responses. With recent advancements in pathogen detection methods, the importance of polymicrobial disease has become more evident, and identification of interactions of pathogens and their mechanisms of disease potentiation has become a topic of great interest. For example, combined infection of pigs with typically low pathogenic organisms like PCV2 and MHYO results in severe respiratory disease. Although the body of knowledge has advanced substantially in the last 15 years, much more needs to be learned about the pathogenesis and best practices for control of swine respiratory disease outbreaks caused by concurrent infection of two or more pathogens. This review discusses the latest findings on polymicrobial respiratory disease in pigs.

scholarly journals A Novel Neuraminidase-Dependent Hemagglutinin Cleavage Mechanism Enables the Systemic Spread of an H7N6 Avian Influenza Virus

mBio ◽  
2019 ◽  
Vol 10 (6) ◽  
Author(s):  
Hyeok-il Kwon ◽  
Young-Il Kim ◽  
Su-Jin Park ◽  
Eun-Ha Kim ◽  
Semi Kim ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Influenza A ◽  
Systemic Infection ◽  
Influenza Viruses ◽  
Mallard Duck ◽  
Virulence Markers ◽  
Systemic Spread ◽  
Cleavage Motif

ABSTRACT In this study, we demonstrate a novel mechanism for hemagglutinin (HA) activation in a naturally occurring H7N6 avian influenza A virus strain, A/mallard duck/Korea/6L/2007 (A/Mdk/6L/07). This novel mechanism allows for systemic infection of chickens, ducks, and mice, and A/Mdk/6L/07 can replicate in vitro without exogenous trypsin and exhibits broad tissue tropism in animals despite the presence of a monobasic HA cleavage motif (PEIPKGR/G). The trypsin-independent growth phenotype requires the N6 neuraminidase and the specific recognition of glycine at the P2 position of the HA cleavage motif by a thrombin-like protease. Correspondingly, viral growth is significantly attenuated by the addition of a thrombin-like protease inhibitor (argatroban). These data provide evidence for a previously unrecognized virus replication mechanism and support the hypothesis that thrombin-mediated HA cleavage is an important virulence marker and potential therapeutic target for H7 influenza viruses. IMPORTANCE The identification of virulence markers in influenza viruses underpins risk assessment programs and the development of novel therapeutics. The cleavage of the influenza virus HA is a required step in the viral life cycle, and phenotypic differences in viruses can be caused by changes in this process. Here, we describe a novel mechanism for HA cleavage in an H7N6 influenza virus isolated from a mallard duck. The mechanism requires the N6 protein and full activity of thrombin-like proteases and allows the virus to cause systemic infection in chickens, ducks, and mice. The thrombin-mediated cleavage of HA is thus a novel virulence determinant of avian influenza viruses.

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